Mesh.IntersectSubset(Int32,Vector3,Vector3,IntersectInformation) Method (Microsoft.DirectX.Direct3D)

Article
06/30/2006

Intersects the specified ray with a given mesh subset.

Definition

Visual Basic Public Function IntersectSubset( _
    ByVal attributeId As Integer, _
    ByVal rayPos As Vector3, _
    ByVal rayDir As Vector3, _
    ByRef allHits As IntersectInformation _
) As Boolean

C# public bool IntersectSubset(
    int attributeId,
    Vector3 rayPos,
    Vector3 rayDir,
    out IntersectInformation allHits
);

C++ public:
bool IntersectSubset(
    int attributeId,
    Vector3 rayPos,
    Vector3 rayDir,
    [Out] IntersectInformation% allHits
);

JScript public function IntersectSubset(
    attributeId : int,
    rayPos : Vector3,
    rayDir : Vector3,
    allHits : IntersectInformation
) : boolean;

Parameters

attributeId System.Int32
Attribute identifier of the subset to intersect with.

rayPos Microsoft.DirectX.Vector3
A Vector3 structure that specifies the origin coordinate of the ray.

rayDir Microsoft.DirectX.Vector3
A Vector3 structure that specifies the direction of the ray.

allHits Microsoft.DirectX.Direct3D.IntersectInformation[]
Array of IntersectInformation structures that describe all intersections of the ray and the mesh.

Return Value

System.Boolean
Value that is true if the ray intersects a triangular face on the mesh; otherwise, the value is false.

Remarks

This method provides functionality that is similar to that of Intersect.

The IntersectSubset method provides a way to understand points in and around a triangle, independent of where the triangle is actually located. This method returns the resulting point by using the following equation:

V1 + U(V2-V1) + V(V3-V1)

Any point in the plane V1V2V3 can be represented by the barycentric coordinate (U,V). The U parameter controls how much V2 gets weighted into the result, and the V parameter controls how much V3 gets weighted into the result. Lastly, 1-U-V controls how much V1 gets weighted into the result.

Barycentric coordinates are a form of general coordinates. In this context, using them represents a change in coordinate systems. What holds true for Cartesian coordinates also holds true for barycentric coordinates.

Exceptions

InvalidCallException

The method call is invalid. For example, a method's parameter might contain an invalid value.

OutOfMemoryException Leave Site

Microsoft Direct3D could not allocate sufficient memory to complete the call.

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Mesh.IntersectSubset(Int32,Vector3,Vector3,IntersectInformation) Method (Microsoft.DirectX.Direct3D)

Additional resources

Visual Basic	Public Function IntersectSubset( _ ByVal attributeId As Integer, _ ByVal rayPos As Vector3, _ ByVal rayDir As Vector3, _ ByRef allHits As IntersectInformation _ ) As Boolean
C#	public bool IntersectSubset( int attributeId, Vector3 rayPos, Vector3 rayDir, out IntersectInformation allHits );
C++	public: bool IntersectSubset( int attributeId, Vector3 rayPos, Vector3 rayDir, [Out] IntersectInformation% allHits );
JScript	public function IntersectSubset( attributeId : int, rayPos : Vector3, rayDir : Vector3, allHits : IntersectInformation ) : boolean;

attributeId	System.Int32 Attribute identifier of the subset to intersect with.
rayPos	Microsoft.DirectX.Vector3 A Vector3 structure that specifies the origin coordinate of the ray.
rayDir	Microsoft.DirectX.Vector3 A Vector3 structure that specifies the direction of the ray.
allHits	Microsoft.DirectX.Direct3D.IntersectInformation[] Array of IntersectInformation structures that describe all intersections of the ray and the mesh.